This invention relates to a resonant cavity structure for an ion laser.
This invention relates particularly to a resonant cavity structure (a) which separates the functions of (1) longitudinal positioning of the mirror mounting plates and (2) rotation and/or lateral shifting of the mirror mounting plates, and (b) which utilizes specific materials best suited for accomplishing each of these separate functions and (c) which decouples the geometry of the cavity structure from the location of the contact points for the mirror adjusting screws.
Ion lasers, such as, for example, Argon and Krypton ion lasers, are often used to provide single mode operation so that the laser operates at a truly single frequency. Operation in a single longitudinal mode at a truly single frequency is highly important for applications such as holography, laser doppler velocimetry, and other applications which depend on having a truly single color laser.
Because of the nature of the modes that can be produced under the gain curve of an ion laser, any change in the overall length of the cavity can create problems in maintaining a truly single frequency. To prevent such problems, the distance between the end mirrors has to be made extremely stable with respect to both temperature and vibration. A resonator structure is a basic and important part of the laser cavity, because the resonator structure provides the mirror mounting plates for the cavity.
The prior art techniques for holding the mirror plates stable have not been entirely satisfactory.